(_a_) In the first place, the law might mean that action always follows the course which, as a matter of fact, will in the long-run bring the greatest balance of pleasure to the agent. It is evident that there is no ground in psychology for maintaining this view. Yet it is a fair interpretation of the "law" of psychological hedonism, as commonly stated; and it is at least an admissible supposition that this meaning of the phrase has not been without effect upon the uses to which the law has been put by some of its upholders. The second interpretation of the law--namely (_b_), that action is always in the direction which seems to the agent most likely to bring him the greatest balance of pleasure, whether it actually brings it or not--is the sense in which it appears to have been most commonly taken when expressed with any degree of accuracy. It is in this sense that--in language which ascribes greater consistency to men's conduct than it usually displays--"interest" is asserted by the author of the 'Système de la nature' to be "the sole motive of human action."[16] The same view is adopted by Bentham;[17] and both James Mill and John Stuart Mill identify desire with pleasure, or an "idea" of pleasure, in terms which are sufficiently sweeping, if not very carefully weighed;[18] while the will is said to follow desire, or only to pass out of its power when coming under the sway of habit.[19] Still another meaning may, however, be given to the "law" of psychological hedonism, according to which the doubtful reference to the manifold pleasures and pains, contemplated as resulting from an action, is got rid of, and (_c_) the agent is asserted always to choose that action or forbearance which is actually most pleasant, or least painful, to him at the time--taking account, of course, of imaginative pleasures and pains, as well as of those which are immediately connected with the senses. It is in this interpretation of its law that psychological hedonism seems to be most capable of defence, and in this sense it has been more than once stated and defended.[20] [Sidenote: 2. Ethical inferences from this theory,] The ethics of the form of Naturalism which is now under examination must be inferred from the "law" that human action follows the greatest pleasure, in one or other of the above meanings which that law admits of. The law is the datum or premiss from which we are to advance to an ethical conclusion. The "right" is to be evolved from the pleasurable; and the pleasurable, consequently, cannot be made to depend upon the right. It is certainly true of the conduct of most men, "that our prospect of pleasure resulting from any course of conduct may largely depend on our conception of it as right or otherwise."[21] But this presupposes that there is a right independent of one's own pleasure, and therefore does not apply to an ethics based on the simple theory of human nature put forward by psychological hedonism.